Air-distribution system

ABSTRACT

An air-distribution system comprises a fluid device that enables deviation of a flow of air that traverses a main duct ( 6 S;  6 D) into a first secondary duct ( 7 S,  7 C) and a second secondary duct ( 7 C,  7 D), exploiting the Coanda effect. The system may be applied in vehicles in general, in particular motor vehicles, or for example in residential, commercial and industrial buildings.

This is a National Stage Entry of Application No. PCT/EP02593 filed Mar.8, 2002; the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to air-distribution systems in general,for instance for use in residential, commercial or industrial buildings,or else in motor vehicles, the air-distribution system according to theinvention being of the type comprising:

at least one inlet duct for a flow of air;

a plurality of mouths for outflow of the air into an environment; and

an air-distributing device, comprising:

an inlet (3), which receives the air-flow from the aforesaid inlet duct;and

a plurality of outlets, located at a distance from said outflow mouthsand connected to the latter by respective pipes.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an air-distributionsystem of the type specified above, which is simple and of reliable andefficient operation. With a view to achieving this objective, thesubject of the present invention is a system of the type referred toabove, characterized in that said air-distributing device furthercomprises:

a passage (6S; 6D) connected to said air-flow inlet duct, and

fluid means associated to said passage for deviating the air-flow in onefirst or one second direction (7S, 7C; 7D) by the Coanda effect.

According to a further characteristic of the present invention, saidpassage is constituted by a main duct (6S; 6D), which has one inlet endand which comes out at the opposite end in a first secondary duct (7S,7C) and a second secondary duct (7C, 7D), which branch off from the mainduct according to two distinct directions, and said fluid means aredesigned to modify the geometry of the main duct in such a way as tocontrol the direction of the flow by the Coanda effect.

According to yet another characteristic of the invention, said fluidmeans comprise:

one or more control openings (9) made in one wall (8) of the main duct,

obturator or perturber means (10) co-operating with said openings anddisplaceable between an inactive condition and an active condition.

the wall in which the control openings are made being set parallel tothe direction of air flow in the duct, in such a way that theintervention of said fluid means does not substantially involve anyvariation in the air-flow rate through the main duct.

It should be noted that the U.S. Pat. No. 4,686,890 and thecorresponding European patent No. EP-B-0 174 660 illustrate theapplication of fluid means to a mouth for outflow of air into thepassenger compartment of a motor vehicle. The said document does nottherefore anticipate the invention in so far as it does not refer to adistributing device set upstream of the air-outflow mouths and at adistance from the latter. In addition, the fluid means provided in thiscase affect the flow rate of the air in the main duct. The same appliesto the outflow mouth illustrated in the U.S. Pat. No. 4,407,186, whichenvisages a hybrid solution comprising both a fluid element andconventional deflecting fins, in which use is made of auxiliary controlflows that are taken from the main flow.

The invention relates to a distribution device set upstream of, and at adistance from, mouths for outflow of the air into the environment, whichis able to control selective sending of air to the various mouths,preventing the head losses that are generated in the ducts that use theconventional deflecting fins and without involving the flow-ratevariations, which occur in the known solutions of outflow mouthsequipped with fluid means. The arrangement according to the presentinvention enables advantages to be obtained at the level of aerodynamicefficiency, as well as of the simplicity and of the reduced overalldimensions of the structure of the device. In addition, the invention issuitable for being used to provide, according to criteria of modularity,simultaneous control of the direction of a number of air flows that passthrough a plurality of main ducts set alongside one another, each ofwhich comes out into two secondary ducts and has a respective controlopening. In this case, according to the invention, the control openingsof the various main ducts are aligned with one another, and theobturator means associated to said control openings are in common. Theymay comprise, for instance, two or more rotating cylinders, each havinga wall with a distribution of openings, such that the said cylindersprovide the different possible combinations of opening and closing ofthe various control openings in their corresponding different positions.This specific solution is suitable for being used in a particularlyadvantageous way in an air-distribution system in a motor vehicle. Theobturator means described above present, in fact, particular advantageson account of their reduced dimensions, their simplicity, and theirreduced energy consumption. A single actuator comprising the pair of tworotating cylinders is able to control the flow of air through aplurality of outlets of the distribution system.

The Coanda-effect air distributor described above can be made so as tobe monostable or bistable. In the first case, the flow of air deviatespreferably from the main duct into a first secondary duct, and switchingto the second secondary duct is obtained only as long as a controlsignal is generated, such as a secondary flow of air leaving the controlopening.

If the air distributor is bistable, instead, it is able to switch theoutflow of air from the first secondary duct to the second secondaryduct, or vice versa, whenever a control signal is generated (as, forexample, removal of the obturator from the control opening), but remainsin the new switched condition even when the control signal ceases. Thisresult can be obtained, for instance, by providing two control openingson the two opposite sides of the main duct, which are opened selectivelyto cause deflection of the main flow of air towards the first secondaryduct or towards the second secondary duct, respectively.

Control of the obturator or perturber means can be obtained in any way,for example with traditional actuators (electromagnetic, hydraulic,pneumatic) or piezoelectric actuators, or electrorestrictive polymers,or shape-memory actuators.

As has been seen, the control signal that enables the flow to be startedin a first direction or in a second direction is preferably generated bycontrolling a control opening. This opening can set in communication themain duct traversed by the air flow with an environment at lower orhigher pressure. The obturator means can consist of moving surfaces, asin the case of the example using the two rotating concentric cylinders,or even of deformable surfaces. In the case of bistable distributors,the control signal can also be generated by a thermal perturbation or bya perturbation generated by jets of air of pre-determined intensity andduration.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages will emerge from the ensuingdescription with reference to the attached drawings, which are providedpurely by way of non-limiting example, and in which:

FIG. 1 is a perspective view of an example of embodiment of the systemaccording to the invention, which can be used as an air distributor in amotor vehicle;

FIG. 2 is a cross-sectional view at an enlarged scale according to theline II—II of FIG. 1;

FIG. 3 is a cross-sectional view according to the line III—III of FIG.1;

FIG. 4 is an exploded perspective view of the obturator means used inthe system of FIG. 1;

FIGS. 5 and 6 illustrate a detail of FIG. 2 in two different operatingconditions in order to illustrate the operating principle of the systemaccording to the invention;

FIG. 7 illustrates the developments in plan view of the walls of the tworotating cylinders that constitute the obturator means of the deviceaccording to the invention;

FIG. 8 illustrates a further embodiment of the invention;

FIG. 9 illustrates a specific application;

FIG. 10 is a perspective view of a variant of the assembly of FIG. 1;

FIG. 11 is a plan view of the assembly of FIG. 10;

FIG. 12 is a side view of the assembly of FIG. 10;

FIG. 13 illustrates, at an enlarged scale, a detail of FIG. 12;

FIG. 14 illustrates, at an enlarged scale, a section along the lineXIV—XIV of FIG. 10;

FIG. 15 is an exploded perspective view at an enlarged scale of thedetail of FIG. 13; and

FIG. 16 is a side view at an enlarged scale of a detail of FIG. 12.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1, the reference number 1 designates, as a whole, a structuremade of plastic material that can be used as an air distributor in amotor vehicle. The structure 1 comprises a main section 2 that defines amain duct 3 for the flow of the air (FIG. 3), which enters the ductthrough an opening 4. As may be seen in FIG. 2, the main duct 3 dividesinto two separate ducts 5S, 5D, each of which is prolonged into threemain ducts 6S, and three main ducts 6D, respectively, which are setvertically one above another. Each of the main ducts 6S branches intotwo secondary ducts 7S, 7D, which define between them an angle of lessthan 90° and which exit from the structure 1 at the end opposite to theopening 4. Likewise, each of the three main ducts 6D set vertically oneabove another branches into two secondary ducts 7C, 7D, which formbetween them an angle of less than 90°. Each of the three main ducts 6Sset vertically one above another is delimited on its inner side by awall 8 having a control opening 9 set in a plane parallel to thedirection of flow of the air through the duct 6S. Likewise, each of thethree main ducts 6S set vertically one above another is delimited on itsinner side by a wall 8 having a control opening 9, which is also setlying in a plane parallel to the direction of flow of the air throughthe duct 6D. Since there are three ducts 6S set vertically one aboveanother and three ducts 6D set vertically one above another, the systemenvisages in all three control openings 9 vertically aligned with oneanother for controlling the flow of air that passes through the threemain ducts 6S, and three control openings 9, which are also verticallyaligned with one another for controlling the flow of air that passesthrough the three main ducts 6D.

The different possible combinations of opening and closing of the sixcontrol openings 9 described above are obtained by providing obturatormeans consisting of an obturator device 10 including two concentric androtating cylinders 11, 12 (see FIG. 4). The walls 11 a and 12 a of thetwo cylinders 11, 12 are illustrated, developed in the plane, in FIG. 7.As may be seen from FIG. 7, the said walls have a series of openings 13,which are arranged and shaped in such a way that the different relativepositions of the two cylinders 10, 11 provide the different possiblecombinations of opening and closing of the control openings 9.

At each control opening 9, the open state and the closed state aredetermining for bringing about deviation of the main air flow towardsone or the other secondary duct. This phenomenon is illustrated in FIGS.5 and 6 with reference to a single specific main duct 6D from whichthere branch off two secondary ducts 7C, 7D. In FIG. 5, the controlopening 9 is obturated in that the internal cylinder 11 has one of itsclosed walls 11 a in a position corresponding to the control opening 9.In this condition, the main flow of air that passes through the mainduct 6D flows, by Coanda effect, following the curve of the wall 8, intothe secondary duct 7C. Should the internal cylinder 11 be rotated so asto leave the control opening 9 free (FIG. 6), in order to set incommunication the main duct 6D with an environment that is, forinstance, at a higher pressure, a control fluid signal is generated,which determines deviation of the flow into the secondary duct 7D.

As may be seen in FIG. 4, at the top end the two rotating cylinders 11,12 have toothings 14, 15 respectively, which enable engagement ofcorresponding operating members. Of course, the means designed tocontrol rotation of the two cylinders 11, 12 may be of any known type,as has already been described above. In addition, it remains understoodthat the device illustrated in the attached drawings is here givenpurely by way of example. Obviously, the example illustrated presentsparticular advantages from the points of view of simplicity, reducedoverall dimensions, and modularity. The obturator device 10 may becontrolled by a single actuator, with a very low energy consumption.Thanks to the arrangement described, the head losses in the air ductsare minimal, and this fact guarantees the high efficiency of theair-distribution system.

FIG. 8 illustrates a further example of embodiment, in which thedeviation of the air flow that passes through a main duct 20 into afirst secondary duct 21 or into a second secondary duct 22 iscontrolled, according to criteria of bistability, by means of twolateral oscillating fins 23, 24, respectively, which are associated withtwo respective control openings.

FIG. 9 illustrates the application of a device 1 according to theinvention, which has an inlet 3 and eight outlets 50 connected by meansof respective pipes 51 and outlet mouths 52.

As has already been mentioned, the system according to the invention issuited to being used both in motor vehicles and in air-distributionsystems for residential, commercial or industrial buildings, or in anyother field of use of air-distribution systems (for instance, also inaeroplanes or ships).

FIGS. 11-16 illustrate a variant of the assembly of FIG. 1. According tothis variant, the body of the distributor assembly, designated as awhole by the reference number 100 comprises a plurality of inletconnections 101, which define a passage 102 (FIG. 14), which branchesinto two ducts 103, 104 that give out onto the top face 105 of theassembly. Once again with reference to FIG. 14, a side wall of the inletduct 102 has an opening 106 controlled by a respective rotating cylinder107. As may be seen in FIGS. 11 and 12, two control cylinders 107 thatare mutually coaxial are provided. However, unlike in the case of theassembly of FIG. 1, the two cylinders 107 are not concentric, but areset one as the prolongation of the other. Each one of them controls abank of three pairs of outlet ducts 103, 104. As envisaged in the caseof the assembly of FIG. 1, each of the cylinders 107 (FIG. 10) ismounted so that it can rotate within fins 108 that form part of thestructure of the assembly and has a wall with open portions and closedportions having the purpose of controlling the openings 106. Themovement of the two cylinders 107 is controlled by a single motorassembly set in a casing 109 that forms part of the structure of theassembly and has an output shaft that controls a worm screw 110. Theworm screw 110 meshes with a gear wheel 111 (FIG. 13), which transmitsthe rotation by means of a pinion 112 coaxial with a gear wheel 113,which is mounted so that it turns on the structure of the assemblybetween the two ends facing one another of the two cylinders 107.

As may be seen in FIGS. 15 and 16, the gear wheel 113 has on its twoopposed faces two ratchets 114, 115, respectively, which are connectedin rotation with the wheel 113. Each ratchet 114, 115 co-operates withelastic elements 116 carried by the respective facing ends 107 a of thecylinders 107.

The electric control motor is a reversible electric motor, designed tocause rotation in one direction or in the other of the gear wheel 113,by means of the transmission 110, 111, 112. In each of the twodirections of rotation, the gear 113 transmits its rotation to just oneof the two cylinders 107 by means of a respective ratchet mechanism madeup of one of the two ratchets 114, 115 and of the elastic elements 116that co-operate with it. For each of the two directions of rotation, oneof the two cylinders is driven in rotation—whilst the other cylinderremains stationary—in so far as its respective ratchet can rotate,causing repeated jumps of the respective elastic elements 116.

Of course, without prejudice to the principle of the invention, thedetails of construction and the embodiments may vary widely with respectto what is described and illustrated herein purely by way of example,without thereby departing from the scope of the present invention.

1. An air-distribution system, comprising: at least one inlet duct for aflow of air; a plurality of mouths for outflow of the air into anenvironment; and an air-distributing device, comprising: an inlet (3),which receives the air-flow from the aforesaid inlet duct; and aplurality of outlets, located at a distance from said outflow mouths andconnected to the latter by respective pipes, characterized in that saidair-distributing device further comprises: a passage (6S; 6D) connectedto said air-flow inlet duct; and means associated to said passage fordeviating the air-flow in one first or one second direction (7S, 7C; 7D)by the Coanda effect, towards respective first and second outlets,wherein said passage is constituted by a main duct (6S; 6D), which hasone inlet end and comes out at the opposite end in a first secondaryduct (7S, 7C) and a second secondary duct (7C, 7D), which branch offfrom the main duct according to two distinct directions and lead to saidfirst and second outlets, wherein said deviating means are designed tomodify the geometry of the main duct in such a way as to control thedirection of the flow by the Coanda effect, and wherein said deviatingmeans comprise: one or more control openings (9) formed in one wall (8)of the main duct, and obturator or perturber means (10) co-operatingwith said openings and displaceable between an inactive condition and anactive condition, so as to control the deviation of the main flowtowards said first and second secondary ducts (7C, 7D) by the Coandaeffect, without substantially involving any variation in the air-flowrate through the main duct.
 2. The air-distribution system according toclaim 1, characterized in that said system comprises a plurality of mainducts (6S; 6D) set alongside one another, each coming out into twosecondary ducts (7S, 7C; 7C, 7D) and each having a respective controlopening (9).
 3. The air-distribution system according to claim 2,characterized in that the control openings (9) of the various main ductsare aligned with respect to one another, and in that the obturator means(10) of the control openings (9) are in common.
 4. The air-distributionsystem according to claim 3, characterized in that the common obturatormeans (10) of the control openings (9) comprise two or more rotatingcylinders (11, 12) having walls (11 a, 12 a), which have a plurality ofopenings (13) arranged and shaped in such a way that different possiblecombinations of opening and closing of the various control openings (9)are obtained in the different positions of the two rotating cylinders(11, 12) with respect to one another.
 5. The air-distribution systemaccording to claim 4, characterized in that the two rotating cylinders(107) are set one as the prolongation of the other and present facingends that may be operated selectively by ratchet means (114, 115, 116)controlled by a reversible electric motor (109).
 6. The air-distributionsystem according to claim 4, designed to be used in a motor vehicle,comprising a body (1) including a main section (2) which defines a mainduct (3) that divides into two auxiliary ducts (5D, 5S), each of whichfeeds two or more main ducts (6S; 6D) set vertically one above theother, each main duct (6S; 6D) in turn branching into two, secondaryducts (7S, 7C; 7C, 7D) lying in the same plane as the corresponding mainduct in such a way as to define two sets of two or more outlet openingsset vertically one above another both on the right-hand side and on theleft-hand side of the body (1).
 7. The air-distribution system accordingto claim 6, characterized in that the concentric rotating cylinders (11,12) are set with their axes directed vertically substantially at thecentre of the body (1) of the device so as to control a plurality ofcontrol openings (9), which are set vertically one on top of another ontwo opposite sides of the assembly formed by the rotating cylinders (11,12).
 8. The air-distribution system according to claim 1, characterizedin that the deviating present a bistable operation.
 9. Theair-distribution system according to any one of claims 1 to 7,characterized in that the deviating means present a bistable operation.10. The air-distribution system according to claim 1, characterized inthat the aforesaid obturator or perturber means are controlled by anactuator of a type chosen from among electromagnetic, hydraulic,pneumatic, and piezoelectric actuators, electrorestrictive polymers, andshape-memory actuators.